Generally, the term “synthetic fiber” means an artificial fiber made of synthetic polymer. Synthetic fibers include, but are not limited to, polyester fabric, polyacrylonitrile fabric, polyamide fabric, polyvinyl chloride fabric, polyurethane fabric, polyolefin fabric and polyfluoroethylene fabric, according to the kind of synthetic polymer. These fabrics are made by spinning fusion, solution or emulsion of polymers, and have thermo-plasticity, and are therefore easily melted at high temperature.
Synthetic fibers have slightly different properties according to the polymer used. However, in general, they have light specific gravity and high strengths in tension and friction, and are not easily wrinkled. In addition, they have chemical resistance and are not easily damaged by insects. However, they are inferior in absorptiveness, dyeing property and heat-resistance compared with natural fiber. Thus, it is necessary to pay special attention when treating them and printing something thereon.
When printing a desired object or design on synthetic fiber colored with disperse dye, dyes in the fiber may migrate and be mixed with the ink composition printed thereon, so that the resulting print may be spread and distorted. For example, when printing a white picture onto black-colored fiber, the color of the picture may be changed to gray due to dye-migration.
FIG. 1 shows dye-migration occurring in the printed product, when printing a uniform number on colored synthetic fiber with a conventional method. It shows that the white uniform number was contaminated by the colored dye. On account of this, it is difficult to obtain the desired colors in printing or transcribing team marks or uniform numbers onto clothes such as athletic uniforms made of synthetic fiber, not cotton fabrics. As a result, adhesion of printed matter or embroidery has been applied instead of printing. In these cases, however, marks or numbers adhered onto the uniform may become cracked and cause poor feeling or heterogeneity, resulting in inconvenience.
Under these circumstances, in order to block a disperse dye in a synthetic fiber from migration causing blending thereof, the present inventor has studied extensively on the printing process onto colored synthetic fiber, and found that dye-migration can be blocked by pretreatment with a composition containing activated carbon or by incorporating activated carbon into a resin layer of a transfer paper or into an ink composition in printing on colored synthetic fiber. Based on this finding, the present invention has been completed.